classes.sprites.Box = function(filename, space, pos, size) {
        var body = cp.StaticBody();
        body.setPos(pos);
        var shape = new cp.BoxShape(body, size.x, size.y);
        shape.setElasticity(0);
        shape.setFriction(1);
        shape.setLayers(NOT_GRABABLE_MASK);
        space.addShape(shape);
        var box = cc.Sprite.create(filename, cc.rect(0,0, size.x, size.y));
        box.setPosition(pos.x, pos.y);
        box.body = body;
        return box;
};